In order to clarify future automobile technologies and fuel qualities to improve air quality, second phase of Japan Clean Air Program (JCAPII) had been conducted from 2002 to 2007. Predicting improvement in air quality that might be attained by introducing new emission control technologies and determining fuel qualities required for the technologies is one of the main issues of this program. Unregulated material WG of JCAPII had studied unregulated emissions from gasoline and diesel engines. Eight gaseous hydrocarbons (HC), four Aldehydes and three polycyclic aromatic hydrocarbons (PAHs) were evaluated as unregulated emissions. Specifically, emissions of the following components were measured: 1,3-Butadiene, Benzene, Toluene, Xylene, Ethylbenzene, 1,3,5-Trimethyl-benzene, n-Hexane, Styrene as gaseous HCs, Formaldehyde, Acetaldehyde, Acrolein, Benzaldehyde as Aldehydes, and Benzo(a)pyrene, Benzo(b)fluoranthene, Benzo(k)fluoranthene as PAHs. From the viewpoint of automobile technologies, combustion methods for gasoline engines including Lean-burn Direct Injection Spark Ignition (DISI), Stoichiometric DISI and Multi Point Injection (MPI), aftertreatment systems for diesel vehicles / engines including Diesel Oxidation Catalyst (DOC), urea-Selective Catalytic Reduction (urea-SCR) and catalyzed Diesel Particulate Filter (DPF) were evaluated. As for effect of fuel qualities, Ethanol (EtOH)-blend, Ethyl Tertiary Butyl Ether (ETBE)-blend, Fatty Acid Methyl Ester (FAME)-blend and high aromatic content for gasoline and FAME-blend for diesel fuel, were evaluated.